I'm trying to set up a D-Link 524T (ESL524TEU.A1G ) as a router tech router, but am having set-up problems with the the LAN in firmware 2.97
I've plugged an ethernet cable from my computer into LAN Ethernet#1 on the back of the modem.
The modem is configured to come up as 192.168.1.1 via ADAM2 bootloader.
I can web-browse to 192.168.1.1, and enter USER: Admin PASSWORD: Admin

In the Routertech menus, Setup->Lan Configuration, shows Ethernet, Ethernet2, Ethernet3 and Ethernet4 in "LAN group 1."
I can successfully remove Ethernet2,3,4 from "LAN group 1" without any problems.
The firmware also warns me that I can not remove Ethernet without a number ... I assume that's Ethernet port 1; which is the port the cable is plugged into.

However, when I try to add Ethernet2,3,4 to to another LAN group, the modem stops working and I can no longer ping 192.168.1.1
This appears to be a bug in the router-tech firmware.

How can I work around this problem?

Background information (and) how I flashed the modem after a lot of pain:
I bought the modem used, because the DSL driver is open source; and these modems are very common in Canada and Europe, so that I can buy them cheap.
I want the modem to either run as a pure router for a XFINITY cable modem, or else as a router for a DSL connection.
Right now, the cable modem is cheaper ... so I need to have the D-Link act as a gateway, firewall, DNSMASQ DNS server, DHCP server, and NAT for the ethernet ports #2..4.
The internet is found by running a DHCP client on Ethernet port #1 , to get the DNS upstream servers and dynamic IP address from a motorola cable modem.

I read all the routertech forum threads on this particular modem, and it should be able to do the task.
I found the two defective 100uF 25V capacitors in the DSL-524T mentioned in several threads; they were right next to the Ethernet switch chip (Infineon ADM6996M).
I replaced them and the ping response time of the modem improved dramatically, even when the modem was hot.

Flashing the modem was difficult.
I use Linux and don't have wine/windows, so I had to find the information on the modem by hand and use the ADAM2 FTP bootloader to flash the modem.
I determined that the modem has 4M Flash, so I downloaded: RouterTech_3.6.0D_20120130_2.97 (Adam2-4mb-flash; 20120130225053)
I set up my gentoo linux computer to talk to the DSL-524T modem:

ip address add 192.168.1.2/24 dev enp1s0

I then followed the instructions on other threads to flash the image using FTP.

The new firmware refused to run after dozens of tries (I bricked the modem), and I finally figured out that defragmenting of the configuration memory wasn't happening because the routertech firmware wasn't booting.
The only way I could guess that would defragment the environment variables, was to manually delete all variables using Adam2, and then re-instantiate them.
There is no documented way to list all existing variables via the FTP/ADAM2 interface, and the telnet port was bricked.
So, I found a list of all common varaibles in Adam2. ( http://wikibin.org/articles/adam2.html )

The bugs in FTP clients on linux vs. ADAM 2 bootloader were severe. Debricking the modem while using an FTP was impossible as many of the response messages weren't printed correctly.
Using netcat to enter RAW FTP/ADAM2 commands for the DSL-245T was easier after a factory reset. That allowed me to see the responses properly.
I wrote down the variable values that my modem had by default, and then had a friend with windows run a scan on the firmware to get proper mtd0..4 address ranges.
So, you should check your default values by doing GETENV before setting them, as your values might differ ... esp: bootloaderVersion, firstfreeaddress, and mac_ap, maca can be found on the sticker of your modem.

nc 192.168.1.199 21 # The modem factory reset went to 192.168.1.199 on my modem. Weird. To defragment variables, I did: